1. Field of the Invention
This invention is concerned primarily with an improvement relating to, or in, a cleaning apparatus for removing any raw material adhering to the inner wall of a raw material transfer pipe for transferring a viscous or powdery raw material.
2. Description of the Prior Art
When viscous raw materials such as thick malt syrup, ice cream, etc, or powdery raw materials such as flour are transferred from a storage tank to a site or to processing equipment through a transfer pipe, it has been standard practice to divide the transfer pipe into small zones and to periodically clean each zone because raw material adheres to the inner wall of the transfer pipe, but disassembling and reassembling the pipe is troublesome and time consuming. Particularly when the raw material to be transferred is foodstuff, cleaning must be done for reasons of sanitation whenever the transfer is complete. Besides the troublesome cleaning, the quantity of the raw material discarded at the time of cleaning is significant; hence, the yield is reduced.
To eliminate the problem described above, the prior art references such as Japanese Utility Model Publication No. 45832/1983 and Japanese Patent Laid-Open No. 100754/1977, for example, propose a system in which a pressure-receiving member for receiving pressurized water is fitted into the transfer pipe, and is pressure-fed by the pressurized water, thereby rinsing off and removing the raw material adhering to the inner wall of the transfer pipe.
However, a problem with a cleaning device of the kind described above is that since a pressure-receiving recessed region of the cleaning member is not curved to match the cross-sectional shape of the transfer pipe at the curved region of the pipe, its contact with the wall on the reduced diameter region of the transfer pipe is not sufficiently close, the pressurized water for the pressure feed leaks from this portion to impede the transfer of the cleaning member, and residue adhering at that region can not be reliably wiped off and removed. If any steps or recesses exist on the inner wall of the transfer pipe, the leakage of the pressurized water takes place at these places, whereby the pressure-feed of the cleaning member is also less effective.